The chimpanzee is a primate species closely related to the human. The species has been shown to be of great use in the study of endocrine, physiologic, medical and cognitive factors. Previous research has been directed to the investigation and improvement of artificial breeding methods for the chimpanzee. That work was undertaken in order to supplement the chimpanzee breeding program, thus ensuring the continued availability and viability of the captive population and eliminating the need for further removal of animals from the wild. The proposed work will continue to develop previous work related to artificial breeding and realization of the potential genetic diversity within the existing captive population; will extend the use of the existing captive chimpanzee population in conservation of other endangered species e.g. (P.paniscus) and will extend our use of IVF techniques in other nonhuman primates for investigation of the mechanism of transfer of immunity to SIV and HIV; and will conduct studies which will provide information relevant to future use of the chimpanzee in study of health related problems directly related to women, e.g., subfertility and premenstrual syndrome (PMS). Specifically, we propose to: 1. Improve identification and control of the 'normal' endocrine changes associated with the menstrual cycle of the chimpanzee with particular reference to the role of prolactin and oxytocin in modification of luteal function; 2. Develop methods for the initiation and maintenance of interspecific/intergeneric pregnancy both in monkeys and great apes; 3. Investigate novel methods for the storage of primate spermatozoa at low, but above freezing, temperatures; and 4. Maintain a germ plasm cryobank, with increased use of oocyte storage to further develop the concept of the frozen ark for nonhuman primate species.